Gene sequencing can match patients to best cancer trials

An exploratory study has indicated that identifying the “mutational landscape” of a person's cancer is a promising method of determining which trials are best-suited to the patient's particular case. The new approach may allow researchers to design trials of targeted therapies to help patients with a known molecular target.

In the Michigan Oncology Sequencing Project (MI-ONCOSEQ), investigators from the University of Michigan Comprehensive Cancer Center and the Michigan Center for Translational Pathology (both part of the University of Michigan Health System in Ann Arbor) used a combination of gene-sequencing technologies to find mutations in the tumors of two cancer patients—one with colorectal cancer, one with melanoma—in less than 1 month. This high-throughput sequencing employs the latest technology to process millions of pieces of genetic information, allowing users to map a cancer's genetic aberrations.

A multidisciplinary group of clinical oncologists, geneticists, pathologists, biologists, bioinformaticians, and bioethicists then analyzed the findings from each tumor and identified genetic information that could have an impact on the current treatment of the patients' cancers.

This “sequencing tumor board” determined that only two of the mutations exhibited by the person with colorectal cancer could potentially be matched to clinical trials. These mutations were found in the NRAS and the CDK8 genes. An analysis of the person with melanoma also revealed several mutations, including HRAS, which has not yet been implicated in this form of skin cancer. A potential clinical trial was also found for this patient.

In a statement issued by the University of Michigan Health System, co-lead investigator Sameek Roychowdhury, MD, PhD, who is a clinical lecturer in hematology and oncology at the University of Michigan Medical School in Ann Arbor, remarked that 10 or 20 years ago, this type of gene sequencing would have cost many millions or even billions of dollars. “But the technology is advancing so rapidly, now we're talking in terms of thousands [of dollars], which makes widespread use a real possibility.”

The authors caution in Science Translational Medicine (2011;3[111]:111ra121) that not all patients will match an existing study, and that identifying matching therapies alone does not guarantee that the clinical trial will improve the person's cancer status. Only actually taking part in the given study will demonstrate benefit or a lack thereof.